| A | B |
|---|
| theory | unproven idea |
| continental drift | theory that states continents were joined at one time |
| crust | thin, outer surface of the earth |
| mantle | layer of earth on which crust floats |
| core | innermost layer of the earth |
| tectonic plates | sections of the crust that move independently |
| rift | separation of the earth's crust |
| folding | earth's crust buckles in a wavelike pattern |
| fault | a break in the earth's crust |
| lava | hot molten rock at the earth's surface |
| magma | hot molten rock of the mantle |
| earthquake | shaking caused by tectonic movement |
| volcano | tectonic forces cause the mantle to explode outward |
| Alfred Wegener | developed the theory of continental drift |
| San Andreas | major system of faults in California |
| Montserrat | Caribbean Island evacuated due to a volcano |
| Mt. St. Helens | erupted May 18, 1980 in Washington |
| New Madrid | site of major earthquakes in 1811-1812 in Missouri |
| ring of fire | highly active volcanic area around the Pacific Ocean |
| tsunami | large wave caused by earthquakes |
